Characterization and antibacterial activity of hexadecyltrimethylammonium modified silver kaolinite

Abstract

The current study focused on the preparation, characterization and evaluation for antibacterial activity of hexadecyltrimethylammonium modified silver kaolinite (DUAL-ANTIBAX®). DUAL-ANTIBAX® was prepared by adding Ag-Kaolinite with surfactant, hexadecyltrimethylammonium (HDTMA). The prepared samples; Kao (raw kaolinite), Ag-Kao, HDTMA-Kao and DUAL- ANTIBAX® were characterized using an X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning-electron microscopy (FESEM), energy dispersive X-ray (EDX) analyser, zeta potential analysis and dispersion behaviour. The samples were observed to have no structural changes and HDTMA and Ag were successfully loaded on kaolinite. DUAL-ANTIBAX® has a positive value of zeta potential due to the presence of surfactants. The antibacterial activity of these samples was determined by Minimum Inhibition Concentration (MIC) assay against Staphylococcus aureus and Escherichia coli in different saline solution concentrations (0%, 0.01%, 0.1%, 1.0% and 5.0%) and at different time of incubation (30 minutes and 24 hours). As a result, DUAL-ANTIBAX® showed better antibacterial activity at lower concentration of saline solution. Meanwhile, DUAL-ANTIBAX® exhibited better antibacterial activity at time of incubation of 24 hours compared to 30 minutes. This study also revealed that, DUAL-ANTIBAX® was more effective on the Gram positive bacteria compared to the Gram negative bacteria. As a conclusion, DUAL-ANTIBAX® can be used as an effective antibacterial agent due to the combination of Ag and HDTMA on kaolinite as a carrier system. Results from this study has highlighted the potential use of DUAL-ANTIBAX® as antibacterial agent and may have an implications to the development of new antibacterial agent.